Mars, Stars, and Life's Origins
Probes like Spirit must find the 'right stuff,' like water
Humans on their tiny planet have found a stellar way to usher in a new year, if not a new era.
In recent days, they've successfully probed the planet Mars, a comet, and the galaxies in separate attempts to discover the essential ingredients for organic life beyond Earth.
Like the earliest ocean explorations of centuries past, these latest technological advances relied on lessons learned from earlier mistakes - especially in reaching Mars. They reaffirm a human desire to know how chemical life began, and whether it can have - or ever had - multiple origins in the universe.
The most spectacular venture was Saturday's landing of the first of two robot-geologists on Mars. The mobile lander Spirit quickly sent back pictures of the Gusev Crater, which is thought by some scientists to be a dry and ancient lake bed with a channel system often associated with liquid water.
Spirit's twin rover, Opportunity, is due to land on Jan. 24 halfway around the planet on another site that has the potential for water. It will search for a type of iron oxide mineral most often found in iron-rich water.
Both golf-cart-sized water seekers are the most sophisticated scientific probes ever sent to another planet. They build on the limited successes of the 1976 Viking landing on Mars and the 1997 explorations by the tiny Sojourner robot, and will bring a whole new sophistication to the geological understanding of the planet.
They are expected to explore more than two miles of Mars - snapping photos, grinding surfaces, and analyzing minerals - for at least three months, with the primary aim of looking for hints of past water, or even reservoirs of ice below the surface, that could suggest Mars was warm and wet billions of years ago.
The NASA probes represent a quickening pace among space-exploring nations to find out if Mars was ever once habitable by some sort of life. Unfortunately, probes sent by Japan and Europe failed in recent weeks, but NASA's success with Spirit and perhaps Opportunity gives hope that more landers will be sent every 26 months, the interval of time for Earth and the Red Planet to draw closest in their orbits.
NASA may have found the right technique for landing unmanned objects on Mars with a combination of rocket deaccelerators, parachutes, and giant airbags.
Two other recent discoveries are also helping humans understand the possible origins of life.
Last week, a NASA mission to the the comet Wild 2 gathered dust and cosmic particles streaming from the comet's nucleus and stored the microscopic material for an expected return to Earth in 2006. These samples could provide answers about basic questions of the origins of the solar system, since comets are relatively pure objects from the system's formation billions of years ago, and whether comets might also distribute key organic materials to planets.
Another recent exploration for life's origin is the first infrared images indicating an abundance of organic compounds in a remote galaxy - a sort of nursery for possible primitive life. In addition, some Australian astronomers have calculated the best places to look for life in the Milky Way, based on the most opportune ages and abundance of life-friendly stars with the right mix of elements.
Inspiring as these discoveries are, they do cost money. All space ventures now come under closer scrutiny, especially after the loss of the Columbia shuttle and its crew last February, and the need to find a stronger purpose for the orbiting space station than international goodwill and a few scientific experiments.
President Bush may announce a vision for a new American space venture in his State of the Union speech later this month, perhaps to help unify the nation around an adventurous goal, just as John F. Kennedy did in 1960 in ordering a moon landing.
The hits and misses of space travel, either manned or unmanned, are often discouraging, but the latest images from Mars and the other recent discoveries are exciting reminders of why the human race can, and must, keep exploring outer space, even if the first simple goal is to find water.